It's natural to want to get the most use out of your products, but in many cases, makeup will expire before we get the chance to use all of it.
Rather than holding on to your foundation for years at a time, it may be wiser to chuck it in the long run – even if you think you're being more resourceful, holding on to makeup too long can lead to unsightly infections.
"If old makeup is contaminated with facial oils, it can cause acne, and if fungal spores or other infectious particles have found a home in your makeup, you risk cross contamination," CBS42.com reports.
According to the news source, you should aim to replace liquid-based makeup after approximately 90 days. If you feel like you'll have trouble remembering, label your makeup with the date on which you opened it.
On that same note, it's probably wise to avoid sharing makeup with others.
"Never use someone else's makeup. Never share makeup. Never share eye drops because the tip of the bottle can be contaminated," Dr. Kathleen Busby told the news source.